I am an enthusiast for scanning aircraft frequencies, and as a private pilot myself also use it to sharpen my comm skills. My question is, does anyone know of any scanning equipment that can be used to pick up "UNIFORM" (military UHF frequencies, ie 225.0 -399.9 MHz.) These regular military frequencies such as the ATIS and Control Tower of most AF bases are not encrypted or classified, so I was wondering if they too can be scanned.

Yes you can with a receiver... not a scanner. Most scanners just cover certain bands popular with the general population (e.g. cops, fire, mcdonald's). I have a Yaesu VR500 that covers everything from 0.0005Mhz to 1500MHz... however my particular model was bought in Japan and does not have cellular phone frequencies blocked out. You can buy the same model but with the 900MHz band blocked here in the United States for about $200. They make some cheaper units too.